| 摘要 |
<p>The hot water is fed through heating radiators, and also to taps in kitchens, bathrooms etc. The boiler has a central hearth, which is surrounded on all sides by a jacket with a double wall; and water is heated while it flows through the jacket. The outer wall of the jacket is pref. covered by thermal insulation and an outer, protective metal casing. The inner wall of the jacket is pref. corrugated to form several deep, hollow fins projecting downwards in the boiler and exposed to the heating gases, to improve heat transfer to the water. Electric immersion heaters are pref. located in the water jacket for use in summer when no fire is lit in the boiler.</p> |
